Roll-up means for flexible strips



Se t. 24, 1968 o. F. VAN HOUTEN ROLL-UP MEANS FOR FLEXIBLE STRIPS 2Sheets-Sheet 1 Filed Aug. 9, 1966 ww [I lllllll lln QN m1 mm mwfi M, .1a W ww @WIQIPMW ii|a '1 N w L Mm \N WTW Mn \N A 7' TORNEYS.

p 24, 1968 o. F. VAN HOUTEN 3,402,901

ROLL-UP MEANS FOR FLEXIBLE STRIPS Filed Aug. 9, 1966 2 Sheets-Sheet 2FIG.3

INVENTOR. OLIVER E 144 HOUTE'N .4 7' TORNEYJ'.

United States Patent 3,402,901 ROLL-UP MEANS FOR FLEXIBLE STRIPS OliverF. Van Houten, Allentown, N.J., assignor to The Thomas & Betts Co.,Elizabeth, N.J., a corporation of New Jersey Filed Aug. 9, 1966, Ser.No. 571,212 2 Claims. (Cl. 242-107.11)

ABSTRACT OF THE DISCLOSURE A roll-up means for flexible stripscomprising a centrally located shaft journalled between two elongatedside members, said shaft being adapted to roll up the flexible stripthereon. A constant force spring is attached to one of the side membersand to the shaft, and arms are provided at the ends of the elongatedside members and connected between them to prevent twisting of theflexible strip during extension and retraction.

This invention relates to roll-up means for flexible strips and moreparticularly to a new and improved rollup means for flexible strips suchas ribbon, tape, flexible cable or the like.

In many applications, flexible strips such as ribbon, tape, flexiblecable or the like are wound up on reels which are adapted to retract thestrip after the strip has been partially unwound from the reel. Awell-known type of reel comprises a spring-loaded rotatable drum towhich one end of the strip is connected mounted within a housing fromwhich the strip may be withdrawn by the application of a pulling force.Removal of the pulling force causes retraction of the strip into thehousing by means of the spring which is mounted internally of the drum.Where it is desirable to unwind a pair of strips in opposite directions,the strips being wound on the drum, difliculties have been encounteredin preventing the cable from twisting during the extension andretraction thereof. In such applications, it is also desirable that thestrip be subjected to a uniform force during extension and retraction ofthe strip from the reel. It is also desirable to wind up as long alength of flexible strip on a reel of as small a diameter as possible.

It is thus an object of the present invention to provide new andimproved roll-up means for flexible strips which is efficient inoperation and economical in manufacture.

It is a further object of the present invention to provide new andimproved roll-up means for flexible strips which automatically retractsstrips which have been extended therefrom.

It is yet another object of the present invention to provide new andimproved roll-up means for flexible strips which applies a uniform forceto the strip during extension and retraction thereof.

It is still another object of the present invention to provide new andimproved roll-up means for flexible strips which allows extension of twostrips in opposite directions therefrom while preventing twisting of thestrips during extension and retraction.

These and other objects will be evident to those skilled in the art fromthe following description and drawings wherein:

FIGURE 1 is a perspective view of a preferred embodiment of the roll-uptracking guide of the present invention;

FIGURE 2 is a partially sectional view taken along line 2-2 of FIGURE 1;and

FIGURE 3 is an exploded view showing the separate elements of the guideof FIGURE 1.

Referring more particularly to the drawings FIGURES 1-3 show a preferredembodiment of the roll-up tracking means of the present invention. Asshown generally in FIGURE 1, the roll-up tracking means of the presentinvention comprises a pair of side members 10 and 12 havingdiametrically opposite arms 14 and 16 extending therebetween. Arms 14and 16 are journalled at their ends in holes 18 of members 10 and 12.Members 10 and 12 are respectively provided with centrally disposedcircular housings 20 and 21 having chambers 22 and 23. Strengtheningribs 24 are provided on members 10 and 12 to add rigidity thereto.

As shown more clearly in FIGURES 2 and 3, centrally disposed shaft 26 isjournalled at its ends in members 10 and 12. Shaft 26 is fabricated withtwo identical halves 26a and 26b and is slotted as at 28 to receive aflexible strip 30. The identical halves of shaft 26 are placed aroundstrip 30 at substantially the central portion thereof. Strip 30 is thenwound about shaft 26 and has its ends 32 and 34 projecting in oppositedirections. Strip 30 may also be prewound with shaft 26 being insertedinto the core thereof. Ends 32 and 34 may, for example, be attached totwo separate members (not shown) which are normally moved towards oraway from each other. Such a situation arises, for example, when strip30 is multiconductor flat cable acting as a jumper between circuitrywhich is movably mounted within a fixed frame and circuitry mounted onthe frame.

Washers 36 and 38 are slipped over ends 40 and 42 of shaft 26 and arecemented in place. Washers 36 and 38 are adapted to rotate withinannular recesses 46 and 48 in members 10 and 12 and thereby to provideadditional bearing support for shaft 26.

A spirally wound spring 50 is mounted within chamber 23 of housing 21 ofmember 12 and keyed to member 12 by projection 54 slipped into slot 56in housing 21. The other end of spring 50 is aflixed to end 42 by end 60of spring 50 being slipped into slot 62 of shaft 26.

Referring now to FIGURE 3, there are shown more clearly the individualcomponents described hereinabove prior to assembly. Assembly of thesecomponents may be accomplished as follows: identical halves of shaft 26are positioned about the central portion of strip 30 and washers 36 and38 are respectively cemented over ends 40 and 42 of shaft 26 until theyabut against faces 64 and 66 of shaft 26. Strip 30 is then wound up onshaft 26. Spring 50 is positioned within housing 21 in chamber 23 ofmember 12, spring 50 being keyed to member 12 by sliding projection 54into slot 56. End 42 is then slipped through spring 50 and member 12,end 60 of spring 50 being inserted into slot 62 of shaft 26. Washer 38is inserted into recess 48 of member 12. The assembly is completed byjournalling end 40 of shaft 26 in member 10 and inserting washer 36 intorecess 46 in member 10. Buttons 68 are cemented into recesses at theends of shaft 26 to prevent members 10 and 12 from slipping off the endsof shaft 26. Arms 14 and 16 are journalled in members 10 and 12 justprior to completion of the assembly and ends 32 and 34 of cable 30projecting over arms 14 and 16.

In use, one end of strip 30 may be affixed to a stationary member suchas a frame, with the other end of strip 30 affixed to a member which ismovable with respect to the' stationary member, such as a drawer movablymounted within the frame. If, for example, strip 30 is multiconductorflat cable, the individual conductors of the cable might be terminatedto a terminal strip mounted on the frame and to circuit elements on achassis mounted on the movable drawer. When strip 30 is retracted,spring 50 is untensioned so that no torque is exerted on shaft 26 byspring 50. As the ends of strip 30 are extended, shaft 26 is rotated,causing spring 50 to be tensioned. The tensioning of spring 50 creates atorque on shaft 26 which is opposite to the torque exerted on shaft 26by the extension of the ends of strip 30. Spring 50 is of such a naturethat it exerts a substantially uniform torque on shaft 26 for the fulllength that strip 30 is extended. Extension of the ends of strip 30would be accomplished in the above example by withdrawing the movabledrawer from the frame. When it is desired to replace the drawer in itsnormal position within the frame, the tension on strip 30 will berelieved and tensioned spring 50 will tend to return to its norm-allyuntensioned state and thus cause shaft 26 to retract strip 36 aboutshaft 26.

Due to the nature of spring 50, spring 50 has the characteristic suchthat it resists uncoiling with a force that is constant with lineardisplacement. Thus a substantially uniform force will be exerted onstrip 30, both during extension and retraction thereof. By mountingspring 50 at the end of shaft 26, it is possible to roll up a greaterlength of strip about shaft 26 than would be possible if a helicalspring were used which was disposed within the central portion of shaft26. Thus the diameter of spring 50 does not limit the minimum diameterof the central portion of shaft 26, thus allowing a greater length ofcable to be wound about shaft 26.

In order to prevent twisting of the strip during extension orretraction, the ends 32 and 34 of cable 30 are passed over arms 14 and16. The distance between arms 14 and 16 is such that when strip 30 isextended, the tendency of the strip to twist will be counteracted byarms 14 and 16.

Instead of the elongated side members described above, it will beunderstood that members and 12 could also be circular or have any othersuitable configuration. It may also be desirable to enclose theperiphery of the rollup means to prevent dirt, etc., from fouling thewoundup strip. In such a case, it is only necessary that the ends of thestrip protrude beyond the enclosure. The roll-up means may be of anysuitable material such as metal, plastic or the like. Where plastic isused, solvent cementing may be used to assemble the elements of theroll-up means.

Although a specific embodiment of the present invention has beendescribed hereinabove, it will be understood that other embodiments andmodifications evident to those skilled in the art are considered to bewithin the scope thereof.

The present invention is therefore not to be limited by the foregoingdescription and drawings, but rather by the following claims.

I claim:

1. A roll-up tracking means comprising a pair of elongated side members,a centrally disposed shaft journalled at its ends in said side members,said shaft being split in half to form two semicylindrical half members,said half members being provided with oppositely disposed recesses toform a slot when said half members are joined together, a flexible striphaving its central portion disposed within said slot of said shaft,sandwiched between said half members of said shaft, said flexible stripbeing spirally wound about said shaft and having its ends projecting inopposite directions, one of said side members being provided with acentrally disposed circular housing having a chamber opening out towardssaid shaft, a constant force spring positioned within said housing ofsaid side member, said spring being spirally Wound, having one endsecured to said housing of said side member and the other end secured tosaid shaft, a pair of oppositely disposed arms journalled at theirrespective ends at the ends of said side members, said oppositelyprojecting ends of said flexible strip projecting over said arm members,the distance between said arms being such that when said strip isextended, the tendency of said strip to twist will be prevented by saidarms, said other of said side members being provided with a centrallydisposed circular housing having a chamber opening out towards saidshaft wherein said ends of said shaft are respectively provided withrecesses, 21 pair of Washers respectively mounted on the ends of saidshaft and adapted to be journalled within said chambers of said housingsof said side members for rotation therein, a pair of buttons having pinportions, said circular housings of said side members respectivelyhaving centrally disposed apertures, the ends of said shafts beingjournalled in said apertures and said pin portions of said buttons areinserted into the recesses in the ends of said shaft and cementedtherein to prevent said side members from slipping ofi the ends of saidshaft.

2. A roll-up tracking means comprising a pair of elongated side members,a centrally disposed shaft journalled at its ends in said side members,said shaft being split in half to form two semicylindrical half members,said half members being provided with oppositely disposed recesses toform a slot when said half members are joined together, said slot beingadapted to receive a flexible strip to be rolled about said shaft, oneof said side members being provided with a centrally disposed circularhousing having a chamber opening out towards said shaft, a constantforce spring positioned within said housing of said side member, saidspring being spirally wound, having one end secured to said housing ofsaid side member and the other end secured to said shaft, a pair ofoppositely disposed arms journalled at their respective ends at the endsof said side members, the distance between said arms being such thatwhen a strip wound about said shaft is extended, the tendency of saidstrip to twist Will be prevented by said arms, said other of said sidemembers being provided with a centrally disposed circular housing havinga chamber opening out towards said shaft wherein said ends of said shaftare respectively provided with recesses, 21 pair of washers respectivelymounted on the ends of said shaft and adapted to be journalled withinsaid chambers of said housings of said side members for rotationtherein, a pair of buttons having pin portions, said circular housingsof said side members respectively having centrally disposed apertures,the ends of said shafts being journalled in said apertures and said pinportions of said buttons are inserted into the recesses in the ends ofsaid shaft and cemented therein to prevent said side members fromslipping off the ends of said shaft.

References Cited UNITED STATES PATENTS 3,337,156 8/1967 Freund 2421071,313,644 8/1919 Simon.

1,663,836 3/1928 Hall.

1,995,026 3/1935 Gast a- 242-74 X 3,211,496 10/1965 Zaydel.

3,291,416 12/1966 Gionta 242107 3,306,552 2/1967 Nakolan 242-107.11

FOREIGN PATENTS 1,108,692 9/ 1955 France.

1,037,828 8/1966 Great Britain.

WILLIAM S. BURDEN, Primary Examiner.

